This invention relates to an improved folding table of the type having three adjacent and successive hinged sections that in a table assembled configuration form a flat rigidified working platform which is supported by tensioned cable members.
Foldable tables and beds adapted for supporting a prone man are known. Such tables have use for massage and medical purposes and such beds (or cots) have use as transient rest platforms. Such structures have a platform means comprised of two or three sections that are interconnected together by hinges. Previously, cable or chain arrangements, sometimes in combination with spar arrangements, have sometimes been used to provide assembled platform section support; see, for example: Pile 3,359,576; Everett et al. 4,833,998; Romein 4,943,041; O""Brien 4,927,128 and Creasy 1,434,100.
These prior art folding table and bed structures all suffer from various common disadvantages. For one thing, the folded configuration of such a table is typically bulky, cumbersome to move or transport, and subject to damage or loss of components. For instance, in a folding table having a two-section platform that is long enough to support a prone man, each section is at least three feet in length when folded, and the folded table typically has exposed or even protruding components. For another thing, such a folding table is also relatively time consuming and laborious to assemble and disassemble, such a procedure commonly requiring tools, physical strength and perhaps more than one person.
Folding tables incorporating two-sections in the platform characteristically cannot be simply converted into tables incorporating three sections in the platform. The desirable objectives of reducing folded table bulk and weight, and of increasing portability and transportability, are not easily achieved in a folding table three-section platform structure. A folding table having three sections in its platform presents a whole group of different component and structural problems which are not present in a two-section table.
A folding table is needed that has a three-section folding platform which is supportable perhaps one meter above ground level and which has a length and strength when assembled sufficient for supporting a prone person of at least about two meters in height and at least 80 kilograms in weight. That table needs to be compact, self-contained and light in weight when folded. Such a table would be desirable for many use situations, particularly in massage and medical treatment, but such a table should additionally have when folded its moving components at least partially concealed or enclosed by the folded sections themselves, and the folded table should be easily transported by one person. Also, such a table should be easily assembled and disassembled by one person, and, when assembled, should be substantially rigid. Further, such a table should be of durable construction, and adapted for undergoing an indefinitely large number of conversions from a full storage configuration to a fully assembled configuration. Such a table should preferably be capable of minor adjustments under field conditions to meet different realistic operational situations. So far as now known, such a folding table that meets such criteria has not heretofore been achieved.
The present invention not only achieves a three-section folding table having such criteria, but also provides such table with additional features and advantages.
This invention relates to a new and very useful folding table that incorporates a hinged, three-sectioned working platform in combination with two pairs of supporting legs for supporting the platform in its erected configuration. Each leg pair has a rigidifying leg pair cross brace. The table incorporates a plurality of tensionable cable members both for supporting the platform in its erected configuration and for bracing the legs in their respective erected configurations, and also a pair of erected platform-to-cable load transfer bars.
This invention also related to new and improved structures for the platform sections of multi-sectioned table platforms and the like.
The invention further relates to laterally extendable hinge structures that are useful for interconnecting together adjacent folding platform sections and the like.
The platform sections in the invention table are hinged together so as to be successive and contiguous whereby a middle section is joined on each opposite side thereof to a side of a different one end section. When the table is assembled and erected from a folded configuration, the platform is substantially flat. The platform can have various perimeter configurations, depending upon section sizes, but a present preference is for the platform to have when unfolded and erected a quadrilateral, more preferably a rectangular quadrilateral, perimeter that is sized for the support of a prone man, for example, a man having the size and weight values above-indicated. The two opposite end sections are preferably beveled (that is, rounded) along the perimeter of each of their respective exposed outside two corners. Preferably, the sections are hinged together so as to permit the opposite end sections to be each folded inwardly relative to the middle section and away from the erected platform surface through approximately 180xc2x0 with one section when folded overlying the next adjacent section.
Preferably, the three platform sections have similar but somewhat different individual measurements. Breadth measurements of the respective sections, for example, may be varied for specific purposes in a given table embodiment. Thus, when the inventive table is folded, the three folded platform sections have adjacent faces and the section edges along at least one platform side coact to provide a single, generally flat face that may be placed on a floor surface in the same general manner as a briefcase bottom. Preferably handle carrying means are associated with a top face of the folded platform sections, the top face being opposite the floor-engaging face.
Each of the opposite end sections is connected to the center section by hinge means. Conventional hinge structures may be used. However, the hinge means employed between the center section and one end section is preferably adapted to provide a pivot region that is effectively spaced below the bottom of platform so as to achieve a separation of these sections in the folded platform configuration. In an illustrative but presently preferred embodiment of the present invention, a second one of the two opposite end sections is so connected by hinge means to the center section that the second end section is adapted to overlie the first end section in parallel, adjacent relationship after each of the first and the second end sections have been folded through 180xc2x0 so to rest adjacent to back side of the middle section in overlying relationship.
The presently preferred table structure preferably provides this section separation when in the folded configuration with no hinge elements extending below about the bottom edge of the platform surface when the platform is in the unfolded position. This preferred structure enables the inventive table platform to be used, if desired, as a mat on a flat surface with the sections unfolded, but with the legs and support structures remaining folded beneath and preferably within the bodies of the panel sections.
A first end section can utilize a conventional type of first hinge structure for foldable connection to the center section. The second end section can employ various second hinge structures, but such a second hinge structure should be laterally extendable. Thus, such a preferred second hinge structure incorporates a hinge, leaf member pair wherein one respective end portion of each leaf member is engaged with the other by, interdigitated knuckle members and wherein each hinge leaf member is laterally extendable relative to, and when extended is spaced from, the other. Preferably, this second hinge structure for the second end section includes a hinge link structure to which each leaf member is pivotably joined by a pintle means so that each leaf member of the pair is selectively slidably laterally extendable relative to the other yet remains pivotable relative to the pintle means. Thus, with such a hinge structure, each leaf member can be connected to a different one of two adjoining sections (here, the middle section and the second end section). In the platform erected (i.e., open or flat) configuration, the sides of these adjoining platform sections are in adjacent relationship with the individual leaf members having adjacently oriented faces; but, in the platform folded configuration, these adjoining sections and their associated hinge leaf members are in spaced, adjacent relationship. The spacing between the leaf members in this folded configuration is sufficient to accommodate the thickness of the previously folded first end section whereby the folded second end section can overlie the folded first end section. The present invention provides an illustrative but presently preferred embodiment of such laterally extendable hinge structure.
Each pair of the supporting legs is preferably longitudinally and symmetrically spaced from the other with each pair being associated with a different one of the two end sections. Each pair has its individual leg members interconnected together, preferably in a midregion thereof, by a different one rigidifying cross brace. Preferably, the upper end of each leg member is pivotally associated with a portion of the underside of a different one of the end sections. Preferably, each individual leg is so pivotally joined to an end section outside corner region. Preferably, each leg is similarly constructed and comprised of telescopically interconnecting elongated tubular sections, most preferably comprising two such sections.
Each leg, preferably in a mid-region thereof, is preferably directly or indirectly associated with an end region of each one of two different cable members. A first such cable member extends upwardly and diagonally to an adjacent longitudinal side portion of the associated end section and is connected thereto. The second such cable member extends upwardly and somewhat diagonally to an adjacent outside end portion of the associated end section and is connected thereto. Preferably, each leg of each leg pair in the table erected (unfolded) configuration is slightly canted outwardly when the leg pair is erected and extended. In the leg erected configuration, the respective length of each of the two leg-associated cable members is such that each cable member extends straight. These leg-associated cable members function to brace and restrain the associated leg from rotating or from moving longitudinally or transversely outwardly.
For structural reasons, preferably these cables are associated with each end of a cross brace located adjacent to and interconnecting with each leg of a leg pair. The legs and cables cooperate so that, when the legs are in their down and locked (erected) positions, the inner and outer leg cables are held taut by the cross member and the legs cannot rotate in either direction. When unlocked and the legs are pivoted upwards into a folded position, sufficient slack is created in the cables to allow the legs to be pivoted to their closed (i.e., folded) position.
When the inventive table is in its erected (unfolded and assembled) configuration, the three platform sections are unfolded and cooperate to define the working platform. To maintain this platform in its erected (unfolded) configuration, and to permit the platform to support loads, a pair of elongated platform support cables are preferably employed whose respective opposite ends are directly or indirectly fixed to respective opposite longitudinal end portions of the platform. Thus, an elongated cable member preferably extends generally along, under, and in inwardly spaced relationship to, each opposed longitudinal side portion of the flat platform while the opposite end of each respective cable is preferably fastened to an opposite outer end portion of each end section.
An elongated rigid platform-to-cable load transfer bar (or truss leg assembly) is preferably provided for each cable. Each bar is preferably positioned so as to extend downwardly from a different opposite longitudinal side region of the platform and preferably is in the same vertical plane as that of one cable in the erected configuration. Preferably, one load transfer bar is associated pivotably with each platform end section at a location adjacent to the platform center section. Engagement of each cable member with its associatable bar can be achieved, if desired, after the platform is unfolded. The relationship between each cable member and its associated bar is such that, when the three platform sections are fully open so to define the flat working platform, each cable member is tensioned so that it angles diagonally downwardly from each platform end region to the associated load transfer bar. Thus, weight on the platform upper or top surface is transferred through the bars to the cable members which effectively act as load carriers.
One now preferred embodiment employs at least one telescoping platform-to-cable load transfer bar. Such a bar advantageously minimizes weight. For improved rigidity, an inventive table may have two platform-to-cable load transfer bars, both collinear with their respective cable members, one telescoping and one not telescoping. As can be seen in a side view of a table embodiment assembly, these bars are preferably slanted slightly inward. Preferably the bars have telescopically interconnecting sections so that the associated cable (xe2x80x9ctruss cablexe2x80x9d) may be engaged in a notch at or across the bottom end of each bar so that then an associated cable can be brought to a lightly tensioned state by extending each platform-to-cable load transfer bar to its full length. Each bar is then held from rotating to a closed configuration preferably by the geometry of the cable/transfer bar and each bar is preferably held from rotating further open by a backstop means in its hinge design. Preferably, all cable tension adjustments are achieved by threaded screw means at the outer section edges, such as eye-bolts or the like.
To permit the assembled and erected table to be folded, each load transfer bar is pivotally mounted adjacent to the inside end of each end section and is adapted for pivoting so as to be adjacent the associated end section underside yet remains adapted for erection when the table is erected for use. To permit adjustments in cable tensioning, preferably the longitudinal length of each load transfer bar is adjustable.
Preferably, the platform sections each comprise a peripheral frame structure comprised of interconnecting components that are themselves comprised of molded plastic or the like. The components are fastened together with an adhesive or other means. Such a frame structure permits virtually infinite permutations in table geometry.
Preferably, platform sections each have panel surface portions that are preferably defined by a perimetrically flanged plate-like member that is received on a frame structure and is fastened thereto with an adhesive or other means. Preferably, each plate-like member is a composite, sandwich-type panel comprising of two thin, opposed outside skins with a honeycomb-type core structure bonded therebetween. For added rigidity without added weight, the lower skins may be formed with raised areas such as beads, ribs or the like in surface areas where the raised areas will not conflict with folding of table components.
Preferably, the entire subassembly of platform supporting components for the platform""s erected configuration is positionable beneath or within the various three sections when the table is in its folded configuration.
When, and if, a platform is adapted for positioning on a floor surface or the like in a stable, flat, unfolded configuration the subassembly of platform supporting components is positionable beneath the sections. Thus, in a preferred embodiment, a person can lie full length or prone on the unfolded platform upper surface without contacting the supporting components.
The upper surface portions of each section can be constructed as desired, depending upon the anticipated end uses contemplated. Preferably, the upper surface portions of each of the platform sections are somewhat resilient or padded, thereby to exert a cushioning effect upon a person lying full length on the unfolded platform.
Preferably, the platform-to-cable load transfer bars each have a section catch means. Preferably, such a section catch means is constructed so that if the erected table, when the platform is unfolded, is lifted by its mid-section for re-positioning, then the end platform sections will not fold downward. Typically, the hinges used in a table embodiment can only support loads in a downward direction. A section catch means preferably achieves this function and avoids end section folding by providing a stop means between the associated edge members of the end and center panels that limits or prevents section folding in an erected table with an unfolded platform.
When in its unfolded and fully erected configuration, the inventive folding table is sturdy, rigid, strong and generally suitable for usage as a table whose platform is load-bearing and adapted for use as a working structure.
When in its folded and fully collapsed configuration, the inventive folding table is preferably easily and conveniently transported or carried by one man. Moving or relatively flexible components are preferably internally housed within the folded associated sections during storage and transport.
The inventive table is relatively lightweight, easy to fabricate, store and use, reliable and durable. It is well suited for many applications, repeated assembly and disassembly, long-term usage, and usage in various environments and conditions.
Particularly when upper surfaces of the platform sections are padded, the inventive table is well suited for use in massage by Feldenkrais practitioners.
When upper surfaces of the platform are unpadded, the table is useful for military applications and field use.
Other and further objects, aims, purposes, features, advantages, embodiments and the like will be apparent to those skilled in the art from the disclosures of the specification taken with the accompanying drawings and the appended claims.